Lab & RGB Spot Colours in PDF files

Serendipity Blackmagic / Veripress 7.1+ feature improved PDF spot colour handling. Lab and RGB special colours defined in PDF files are now recognised and processed using the PDF values when the colours are not listed in the Special Colour Set.

PDF files and spot colour management

When PDF files are submitted, Serendipity Blackmagic and Veripress automatically detects spot colours and attempts to match them with a special colour listed in the Special Colour Set assigned to the Jobticket and/or the system default set.

If match is found for the spots colour(s) in the Special Colour Set, the set colour values – normally Lab – are used and the colour(s) then pass through the special colour path of the colour management system (CMS).

If one or more spot colours in the PDF can not be matched:

  • The job will fail on imaging, reporting the colours that failed to match in the job errors (View Errors option).
  • If an Unknown Specials set is assigned in Server Settings, the unknown spot colour(s) from the job will be added to the set for user reference.
  • Or, when the Use CMYK Simulation from PDF for Unknown Colours is active in the Jobticket > Postscript / PDF Options tab, the CMYK values in the PDF file are used to generate the colours. The colours then pass through the process colour path of the CMS.

Lab and RGB spot colours

In Serendipity Blackmagic / Veripress 7.1+, Lab and RGB spot colour values, stored in the XMP data of PDFs, are now auto-detected and passed through the system.

If match is found for the Lab or RGB spot colour(s) in the Special Colour Set, the set colour values – normally Lab – are used and the colour(s) then pass through the special colour path of the CMS.

If a match is not found:

  • The job will fail on imaging, reporting the colours that failed to match in the job errors (View Errors option).
  • If an Unknown Specials set is assigned in Server Settings, the unknown lab/RGB spot colour(s) from the job will be added to the set for user reference.
  • Or, when the Use CMYK Simulation from PDF for Unknown Colours is active
    • Lab colour values are passed through the special colour path of CMS as Lab spots.
    • RGB colour values are passed through the special colour path of the CMS as RGB device spot colours.

Below are comparative Job Info windows of a PDF with Lab spots, and a PDF with RGB spots submitted with and without a Special Colour Set assigned.

 

Left - Job with Lab spot colour values defined in the PDF Right - Same job with the Lab spot colours matched in the Special Colour Set

Left – Job with Lab spot colour values defined in the PDF
Right – Same job with the Lab spot colours matched in the Special Colour Set

Left - Job with RGB spot colour values defined in the PDF Right - Same job with the Lab spot colours matched in the Special Colour Set

Left – Job with RGB spot colour values defined in the PDF
Right – Same job with the Lab spot colours matched in the Special Colour Set

 

 

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